When installing electrical systems specifically connecting to panels or boxes it is common to drill a hole into the side of the box for access to the internal components of the panel or box. There are many safety protocols against drilling into a box or panel while the boxer panel is live, that is having an electrical current flowing through the box. When drilling metal shavings can fall into components of the box that can cause a short and other damage.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.